Solution of metallo-ammonium naphthenates



Patented Nov. 23, 1943 UNITED STATES .rrmri' oer-ice I 1 I zsssmSOLUTIQNNQF METAIiO-AMIlIONIUM Thomas B. Belser and I Compa In the priorart. exemplified by United States Patent 2,157,727 to Ronald A; Baker,water-soluble complexes of ammonia with zinc or copper and thenaphthenlc acids are prepared by adding a water-soluble salt of themetal, e. g., copper sulfate, to aqueous ammonia,.thus producing thewell known copper-ammonium sulfate. and then adding naphthenic acids inquantity suflicient to produce the naphthenate of the metal. Thequantity of ammonia required is that which pro- Calit, 'assignorsIncorporated. New York, corporation of New York No Drawing. ApplicationMarch 11, 1941, Serial No. 382,767

1 Claim. (01.- ic -so) Harold Schiller, Lol Anto' Socony-Vacunm Oilduces the metallo-ammonium salt plus the quantity required to saponifythe naphthenic acids plus a small excess.

These complexes, which'are used in highly diluted form as agents forpreserving fabrics from rot and for protecting plant life, depend fortheir eflectiveness onthe fact that they are stable only in aqueoussolution and in the presence of the alkaline ingredient, in consequenceof which the naphthenate, which is itself insoluble in water orsubstantially so, is precipitated when films of the solution produced byimmersion or by spraying lose their water and ammonia by evaporation.

In the method ofthis patent the ammonium salt corresponding to themetallic salt taken (i. e., ammonium sulfate in case copper or zincsulfate is used) remains in the film produced by precipitation on dryinand the presence of this byproduct salt is objectionable for severalreasons.

' First, the presence of the salt in a treated fabric materially adds tothe stiffening of the fabric by the treatment. Second, if heat beapplied to dry the wet fabric there is likely to be a decomposition ofthe normal ammoniumssuifate to ammonium hydrogen sulfate and sulfuricacid, which attack both the cloth and the naphthenate film. Finally, ifthe fabric be washed or leached after drying, to remove the ammonium'salt, there is likely to be some hydrolysis, causing some of thenaphthenate film to flake of! and thus render the fabric subject to spotrotting.

, Another drawback to the ammonia process is that the concentration oftheactive metal in the strongest solution possible to prepare is verylow. being of the order of four percent by weight in the case of copper.

We have improved on this process in first preparing the heavy metalnaphthenate in substantially water-free and salt-free form; in placingthis metallic soap in solution in a water-miscible solvent fortransportation and for the convenience of the user, and in adding, theammonia or amine required to make the naphthenate soluble in water onlywhen the product is to be used. .In thismanner we provide the consumerwith TES a liquid product which may be measured for dilution; obtain aproduct in a much higher degree of concentration (of previouslypossible) with a corresponding saving in transportation costs; avoid therisk of loss of ammonia and consequent partial precipitation of thenaphthenate in transit or storage, and eliminate water-soluble saltsfrom the ultimate film of naphthenate.

As a first step we prepare the naphthenate of a metal havingpreservative, fungicidal or insecticidal properties. The metals suitablefor this process, so far as we are aware, are limited to cadmium,copper, cobalt, nickel, silver, and zinc,

acids used are petroleum acids, highly purified and preferably havingacid numbers ranging from 160 to 250 mgr. KOH per gram, equivalent to1110- lecular weights ranging from 850 to 220.

The naphthenate may be prepared in any preferred manner. For example itmay be produced by double decomposition between an alkali metal soap anda water-soluble salt of the heavy metal, in which case the by-productsalts must be washed out and the naphthenate dehydrated by kneading orheating. Or it may be produced by double decomposition in the presenceof a quantity oi a petroleum solvent, the water and salts settling fromthe solution from which the soivent'is' after ward evaporated- Bywhatever manner prepared the heavy metal naphthenate is substantiailydesiccated and freed from salts and then brought into primary solution.For this'purpose we may utilize any of the lower aliphatic alcohols orketones boiling below about 100 Cent. Isopropyl alcohol and methyl-ethylketone are preferred solvents. This is simple solution and may befacilitated by the use of heat if a reflux condenser be provided. I

The solution thus produced is noncorrosive to metallic containers, isindefinitely stable and. may be prepared to contain from 10% to 15% byweight of the active metal.

when the alcoholic solution is to be diluted for use, we add ammoniumhydroxide in such prothe order of three times that.

admit: but without mum onset the increased cost. The concentratedammonia may hemixedwiththepflmnrysolutionormnybe sddedto thewsterotdilutionas preferred.-

By'this addition oi unmonis or in mine the metsllic naphthemte hrendered miscible with water without tion and may be dilutedtosnyextentwhichmubedesirediisumcientottheaminebewesent'l'orvarimisusesitis customnry to dilute it-to containfrom 0.1% to 10 0.6% by weight of the active metal, and in dilutinzbelow1% otthemetnlitlsneoessarytosdd more We therefore prefer to dilutewithamlxtureoiwatci'ninepsrtsbyvolumesnd 28% aqueous ammonia one part.

Weclaimasmuinvention:

' The method 01' bringing norms-11y water-insoluble hesvy metalndphthenntes into ldueous solution which comprises: dissolvin: the neph-6 thennte in a water-miscible solvent selected min the group consistingof the aliphatic alcohols Ind ketones boiling below shout 100 Cents andadding to the solution thus produced 9; 801mm:- ing agent selected fromthe group oonsistin ot ammoniasndthenminesboilingbelowabmstiw' Cent;together with water.

THOMAS R. 3m. HAROLD SCHILLER.

